Re: [BUG] alsa: KMEMLEAK in pulseaudio and alsa-sink-ALC89

From: Mirsad Todorovac
Date: Wed Mar 20 2024 - 14:58:20 EST


On 3/20/24 07:26, Takashi Iwai wrote:
On Wed, 20 Mar 2024 02:13:08 +0100,
Mirsad Todorovac wrote:

Hi,

On Ubuntu 22.04 LTS, with the torvalds tree kernel vanilla v6.8-11167-g4438a810f396,
there is like 660K memory leaks sized 2048 bytes (1.35 GB)

unreferenced object 0xffff919c43c7c800 (size 2048):
unreferenced object 0xffff919c43c78000 (size 2048):
unreferenced object 0xffff919c43c79800 (size 2048):
root@defiant:/home/marvin/linux/kernel/linux_torvalds# grep size ~marvin/linux/kernel_bugs/v6.8-11167/kmemleak.log | wc -l
663265
root@defiant:/home/marvin/linux/kernel/linux_torvalds#

Please find the .config attached.

The kmemleak output is:

unreferenced object 0xffff9199526ba800 (size 2048):
comm "pulseaudio", pid 2533, jiffies 4294900352
hex dump (first 32 bytes):
04 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 ................
49 45 43 39 35 38 20 50 6c 61 79 62 61 63 6b 20 IEC958 Playback
backtrace (crc 87c1dcdc):
[<ffffffffb2fa477b>] kmemleak_alloc+0x4b/0x90
[<ffffffffb210e517>] __kmalloc_node_track_caller+0x3c7/0x530
[<ffffffffb20a102b>] memdup_user+0x2b/0xb0
[<ffffffffc0746d56>] snd_ctl_ioctl+0x726/0x860 [snd]
[<ffffffffb21bed6d>] __x64_sys_ioctl+0x9d/0xe0
[<ffffffffb2f93d33>] do_syscall_64+0x83/0x150
[<ffffffffb3000121>] entry_SYSCALL_64_after_hwframe+0x6c/0x74

Thanks for the report. This was indeed an overlooked marking of
__free(kfree). I'll submit the fix patch.

Takashi

Not at all, thanks for such an early response.

I understand the problems with the incremental development. Actually, great it was caught before
the release ;-)

Best regards,
Mirsad Todorovac